如何在Android中读取自定义属性 [英] How to read custom attributes in Android

问题描述

我可以创建自定义属性并将它们应用于常规的 EditTexts，如下所示:

I can create custom attributes and apply them to regular EditTexts, like this:

<EditText
     android:id="@+id/field1"
     custom:attr1="whatever"
     (...)
<EditText
     android:id="@+id/field2"
     custom:attr1="whatever2"
     (...)

我的问题:我可以在不创建扩展 EditText 的类的情况下读取这些自定义属性的值吗?我的意思是，我想从我的 Activity 中读取自定义属性，但是我目前看到的示例要求我从自定义视图的构造函数中读取值，例如:定义自定义属性

My question: can I read the value of those custom attributes without creating a class that extends EditText? I mean, I want to read custom attributes from my Activity, but the examples I see so far requires me to read the values from the constructor of a custom view, like here: Defining custom attrs

推荐答案

我的问题:我可以不读取这些自定义属性的值吗?创建一个扩展 EditText 的类?

My question: can I read the value of those custom attributes without creating a class that extends EditText?

是的，您无需扩展类即可获得这些属性.为此，您可以在 LayoutInflater 上使用一个特殊的 Factory 集，Activity 将使用它来解析布局文件.像这样:

Yes, you can get those attributes without extending the classes. For this you could use a special Factory set on the LayoutInflater that the Activity will use to parse the layout files. Something like this:

super.onCreate(savedInstanceState);
getLayoutInflater().setFactory(new CustomAttrFactory());
setContentView(R.layout.the_layout);

其中 CustomAttrFactory 是这样的:

public static class CustomAttrFactory implements Factory {

    @Override
    public View onCreateView(String name, Context context,
            AttributeSet attrs) {
        String attributeValue = attrs
                .getAttributeValue(
                        "http://schemas.android.com/apk/res/com.luksprog.droidproj1",
                        "attrnew");
        Log.e("ZXX", "" + attributeValue);
        // if attributeValue is non null then you know the attribute is
        // present on this view(you can use the name to identify the view,
        // or its id attribute)
        return null;
    }
}

这个想法来自 博文，您可能需要阅读它以获取更多信息.

The idea comes from a blog post, you may want to read it for additional information.

此外，根据自定义属性(或其他属性)，您可以只使用 android:tag="whatever" 传递附加数据(然后在 Activity 和 view.getTag()).

Also, depending on that custom attribute(or attributes if you have other) you could just use android:tag="whatever" to pass the additional data(and later retrieve it in the Activity with view.getTag()).

我建议您不要使用这些自定义属性并重新考虑您当前的方法.

I would advise you to not use those custom attributes and rethink your current approach.

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